The invention generally relates to optical switching systems, and particularly relates to wavelength selective optical switching systems and broadband optical switches as well as variable optical channel attenuators.
Optical switches typically involve two or more waveguides that may be selectively brought into close proximity with one another. For example, U.S. Pat. No. 6,839,479 discloses an optical switch that includes a waveguide (having both a core and cladding) mounted on support structures or posts, wherein the waveguide may be selectively deflected toward another waveguide by the application of an electric charge to the waveguide, which includes a doped single crystal silicon conducting element with an electron carrier concentration of 1016 cm−3.
Wavelength selective optical switches typically involve the use of either a ring resonator or a sphere to selectively transfer signals having the selected wavelength from one waveguide to another. For example, U.S. Pat. Nos. 6,665,476 and 6,718,083 disclose wavelength selective switches and routers that include ring or sphere resonators.
A need remains, however, for optical switches and wavelength selective optical switches that provide low-voltage requirements, fast actuation speed, low power, greater reliability, lower optical losses, the ability to be microfabricated (i.e., integrated into a single chip), and compatibility with a variety of material systems including CMOS.
There is a need therefore, for an improved optical switch that is relatively inexpensive to produce yet provides efficient switching of optical signals.